The Internet telephone conversation is known. It has been possible for some time to have a voice conversation over the Internet, or other forms of computer network using a personal computer with a sound card, microphone, and speakers or an earphone. More recently there have been provided dedicated systems comprising a telephone keypad, receiver and screen. However such devices still require a sound card in order to work.
Common methods for voice communication over a computer network employ a sound card on each machine participating in the conversation.
Modified sound cards that enable a telephone to connect to a PC, are commercially available. For example, Phonejack and Linejack, by Quicknet Technology (www.quicknet.net), and Easyphone by Mediasonic (www.easyphone.com) enable a user to make telephone calls over the Internet using a PC related internal ISA card.
U.S. Pat. No. 5,553,122 to Haber et al; U.S. Pat. No. 5,495,246 to Nichols et al.; and U.S. Pat. No. 5,727,047 to Bentley et al. describe methods and apparatus for interfacing computing devices to an analog telephone network.
U.S. Pat. No. 5,473,676 to Frick et al. describes an interface system connected between the telephone base and handset which allows switching between voice and data communications over a single telephone line.
The disclosures of all publications mentioned in the specification are hereby incorporated by reference.